BMI Calculator for Women in Pregnancy
Your pre-pregnancy BMI helps determine healthy weight gain goals during pregnancy. Learn how BMI affects pregnancy health and what weight gain is recommended for your category.
⚠️ BMI calculations during pregnancy are not meaningful
Weight gain during pregnancy is expected and necessary for a healthy pregnancy. Your pre-pregnancy BMI should be calculated using your weight before becoming pregnant.
✓ How to use this guide
- • Calculate your BMI using your pre-pregnancy weight
- • Use your pre-pregnancy BMI category to find recommended weight gain
- • Consult your healthcare provider for personalized guidance
- • Monitor weight gain throughout pregnancy with your doctor
Note: If you're currently pregnant and don't know your pre-pregnancy weight, discuss with your healthcare provider to establish appropriate weight gain goals based on your current health status.
Your pre-pregnancy BMI is one of the key factors healthcare providers use to determine how much weight you should gain during pregnancy. Appropriate weight gain supports your baby's growth and development while minimizing risks for both mother and baby.
28-40 lbs
13-18 kg
25-35 lbs
11-16 kg
15-25 lbs
7-11 kg
11-20 lbs
5-9 kg
Twin Pregnancies
For women pregnant with twins, recommended weight gain is higher:
Too Little Weight Gain
Gaining less than recommended may lead to:
- • Low birth weight baby
- • Preterm delivery
- • Developmental issues
Too Much Weight Gain
Gaining more than recommended increases risk of:
- • Gestational diabetes
- • High blood pressure and preeclampsia
- • Cesarean delivery
- • Larger baby (macrosomia)
- • Difficulty losing weight postpartum
First Trimester
Most women gain 1-5 pounds in the first trimester. Some may lose weight due to morning sickness. This is normal.
Second and Third Trimesters
Steady weight gain is expected:
Calorie Needs
You don't need extra calories in the first trimester. In the second and third trimesters:
Key Nutrients
Prevents neural tube defects
Prevents anemia
For baby's bone development
For tissue growth
For brain development
If you were active before pregnancy, you can usually continue with modifications. Aim for:
- •150 minutes of moderate activity per week
- •Activities like walking, swimming, prenatal yoga
- •Avoid contact sports and activities with fall risk
- •Stay hydrated and avoid overheating
When to Contact Your Healthcare Provider
Reach out if you experience:
- •Sudden weight gain (more than 2 pounds in a week)
- •No weight gain or weight loss in second/third trimester
- •Severe nausea preventing adequate nutrition
- •Concerns about your weight or eating habits
- •Swelling in face or hands (may indicate preeclampsia)
Medical Disclaimer: This information is for educational purposes only. Always follow your healthcare provider's personalized recommendations for weight gain during pregnancy, as individual circumstances may require different guidelines.